Field of the Invention
The present invention relates to a method for film formation, and a pattern-forming method.
Discussion of the Background
In manufacturing semiconductor devices, multilayer resist processes have been employed for attaining a high degree of integration. In these processes, a composition for resist underlayer film formation is first coated on a substrate to provide a resist underlayer film, and then a resist composition is coated on the resist underlayer film to provide a resist film. Then, a resist film is exposed through a mask pattern or the like, and developed with an appropriate developer solution to form a resist pattern. Subsequently, the resist underlayer film is dry-etched using the resist pattern as a mask, and the substrate is further dry-etched using the resultant resist underlayer film pattern as a mask, thereby enabling a desired pattern to be formed on the substrate.
In general, materials having a large carbon content are used for resist underlayer films. When such a material having a large carbon content is used for a resist underlayer film, etching resistance in substrate processing is improved, and consequently, more accurate pattern transfer is enabled. As such a resist underlayer film, a thermosetting phenol novolak resin is well known (see Japanese Unexamined Patent Application, Publication No. 2000-143937). In addition, resist underlayer films formed from a composition for resist underlayer film formation containing an acenaphthylene polymer have been know to exhibit favorable characteristics (see Japanese Unexamined Patent Application, Publication No. 2001-40293).